BMW F90 M5 Catless Downpipes – Straight-Pipe Design for Maximum Flow, Horsepower Gains & Aggressive Exhaust Sound | Fits F90 M5 & Competition Models with S63B44T4 4.4L Twin-Turbo V8 Engine (2018–2023)

Beneath the hood of the F90 M5 lies one of BMW’s most brutal creations — the S63B44T4 twin-turbo V8. But even perfection can be restrained. The factory catalytic converters choke the exhaust flow, muffle sound, and restrict the M5’s full potential. The BAVMODS® Dual Catless Downpipes are engineered to change that — unlocking raw power, quicker boost response, and the thunderous tone your M5 was meant to have.

Engineered for the S63 Twin-Turbo Powerhouse

Each downpipe is crafted from high-grade T304 stainless steel and hand TIG-welded to perfection. Precision mandrel bends ensure a smooth, unrestricted path for exhaust gases, while pre-welded mounting brackets, factory-positioned O₂ sensor bungs, and an integrated heat-sleeve section guarantee a perfect OEM-style fit with race-grade performance. Built to withstand the S63’s immense heat and pressure, this system performs flawlessly whether daily-driven or track-tested.

Key Performance Benefits

• Dual Free-Flow Straight-Pipe Design – Replaces restrictive factory catalytic converters to unleash both turbochargers.
• Faster Turbo Spool – Reduces backpressure for instant boost response and stronger pull through every gear.
• Massive Power Gains – Expect +35–55 HP and +50–70 lb-ft of torque with a proper Stage 2 tune.
• Aggressive Exhaust Tone – Deep, resonant V8 rumble at idle with fierce pops and crackles under load.
• Thermal Efficiency – Integrated heat shielding and sleeve design lower EGTs and protect engine bay components.
• OEM+ Fitment – Direct bolt-on design using factory mounts, brackets, and O₂ locations for seamless installation.

Complete Plug-and-Play Installation

Everything you need for a clean, no-mod install — no cutting or welding required.

Includes:

• Dual stainless-steel catless downpipes (left + right turbo outlets)
• Pre-welded O₂ sensor ports
• Factory-aligned brackets
• Reinforced heat shielding

Pair with a Stage 2 ECU tune for full CEL (Check Engine Light) management and maximum power delivery.

Why Go Catless?

A catless setup is the most effective way to unleash the M5’s true character. By removing restrictive factory cats, you:

• Free up exhaust flow and boost efficiency
• Reduce thermal load and turbo lag
• Enhance sound clarity and aggression
• Unlock tuning potential for higher boost targets
  

This isn’t just a mod — it’s a transformation.

Performance You Can Hear & Feel

From the first cold start to redline, the BAVMODS® Dual Catless Downpipes deliver a visceral driving experience. Quicker spool, harder acceleration, and that unmistakable M-car growl combine to make your M5 feel alive in a way it never has before.

Your S63 deserves freedom — not restriction.

FITMENT: BMW M5 (F90) – 2018 to 2023

ENGINE COMPATIBILITY: S63B44T4 – 4.4L Twin-Turbocharged V8

MATERIAL: High-Grade T304 Stainless Steel (TIG-Welded, Mandrel-Bent, Pre-Welded Brackets & Heat Sleeve Design)

Please refer to the “Fitment” section in the product description for compatibility details.